Resistor mounting for electric furnaces



Oct. 13, 1925. 1,557,104

F. THORNTON, JR

RESISTOR MOUNTING FOR ELECTRIC FURNACES Filed Aug. 18, 1925 ATTORNEY Patented I Oct. 13, 1925.

UNITED STATES PATENr on FRANK THORNTON, JR., OF PITTSBURGH, ENNSYYIVNYE., Si-HQUR v HOUSE ELECTRIC & MANUFACTURING' COMPANY, A Ci'ltGLtlAflUl ll" .1;

RESISTOR MOUNTING FCR ELECTRC d Application lefl August 1 8, 1923.

.To all 107mm 'it may concern:

Be it known that I, FRANK 'l`HoRN'r N, Jr., o citizen of.the United States, sind u resident ot' Pittsburgh, in the county ci Allegheny and Stute of, Pennsylvania, herve invented a ne :incl useful Improvement in Resistor Mountings for Electric Furnaces, of which the following is n specification.

My invention relates to electric furnaces and particularly to electric resistance fue neces.

One object of my invention is to provide o. relatively simple and compact construction for u quickly removable and replaceable heating unit for en electric resistance :tnrnace Another object of' my invention topmvide n relatively high capacity heating unitfor an electric furnace.

Another object of my invention is to providea heating unitfor :in electric furnace that shall comprise supporting.,r means 'tor u resistor operatively engaging e relatively small portion only of the resistor', the resistor being otherwise substantially self-- supporting.

Another object of my invention is to provide e supporting .means that shall permit o'f the free lateral expansion of the resistor member during its operation, while 'pre-- venting-longitudinal movement thereof.

-In practicing my invention, l provide pairs of `relatively narrow, elongated, 'refractory, supporting members, located in parallel s aced relation relatively to eiicli other in t e walls of n furnace, und having one end projecting into the furnace @linnn ber. A, plurality of spaced pockets are provided in the adjacent faces of the refractory members, the pockets in one of the support-- ing members being deeper than those in the other member.

A heeting unit comprises n helio-elly wound coil having flattened, substantially parallel sides and integral rounded edge portions, which latter are located in the respecive pockets in the supporting members.

In the single sheet of drawings,

Figure l` 1s av view, in vertical lateral section, of an electric furnace comprising the device embodying my invention,

Serial it Fig'. is View re'txnctoi resistor si' Fig. is partiel sectI n tlierethrzr 1h., teken on o lll oit .een eieetric itnr'iece "il comprises e milk., .,'1 T .rainy o). eine e l2' nectivel', in i blocks material usually i) 2i, d .x n y desire n inno 'tor each of tl prise e suitable e eeistii'm in mi, Jo

therefor: whieix s? utile i u "f o cated in one of und they in lining .f-nhst.,;ntm.lly left hand wall et Each of the mem of feces the+ fcct L urevty menlierf; 'l5

elrete. l in one er than the for A y Wound coil o resistance mete ",t" coil li v .1 r substantially parallel side-s, and

'founded elge portions. .The rounded. L portions; of each tern the coil 3.7 adipted tti iit into the 'pockets 16 in the of supporting members l. The width of the openingr 16 laterally of the supporting' members 15 ie of substantially the .seme dimension ne the lote-ral width of the coil, 1T. The width of the slots 3 6 longitndineliy of the members i5 is sulistentially th the thickness of Ee resistor .Lin q e 'to aesemnie e heating ,retire @creation reim between the two refractory supporting members is such that the coil may now be moved laterally thereof in a direction to yan cause the lower edge portion to approach the wall of the furnace and clear the other refractor supporting member. lVhen the lower edyge portion -is located above the pockets in the lower refractory member 15, the coil may be dropped so that the lower edge portion operatively engages and fits into the pockets 16 whereb the weight of the coil is supported by the ilower refractory member 15 1n the case of a heatin unit that is located closely adjacent to a si e wall of the furnace.

The ends of the resistor member constituting the heating unit 17 may be brought out through suitable insulating bushings 18 located in the walls of thefurnace near one or both of the refractory sup ortin members 15. If desired, a short ro 19 o a suitable electric conducting material may be located within the bushing 18, and be connected to the end of the resistor wire by a suitable connector 21.

I have illustrated in Fig. 1 of the draw" of the coil is supported by the two ends in-` stead of only by the lower end thereof. The` operation of installation of the coil is, however, the same as hereinbefore described.

lVhen it is necessary or desirable to remove a coil, it is first so moved as to cause the one edge thereof to be disengaged from `that refractory resistor member 15 having ,'shallower pockets therein, which end is then "so moved as to cause this edge of the coil to be free of the outer edge of the supporting member, after which the coil is given a lateral tilting and thenl a lateral movement, causing the other edge portion to be disengaged from the supporting member having the dee r pockets therein.

The evice embodying my invention provides a double-layer coll of resistor material, substantially all of the len h of the resistor member being in heat-ra iating relation to the furnace chamber, that is, only a relatively small portion of its length 1s covered by any other portion thereof. The double-layer helical coil permits of producing a ater amount of heat in a given area of wa surface of the furnace chamber than would be possible if only a single-layer winding were providal.

The spaced pockets in each of the supporting members provide means for holding each of the turns of the helical coil 17 b their edge portions. whereby any longitud1- nal movement of the individual turns and of the entire coil is prevented.

e clearance between-one edge portion of the coil and the bottom of the pockets permits also of the free expansion of the straight portions of each turn whereby any injurious eect of such expansion upon the supporting members is prevented.

Any coil may be easily and quickly installed and removed without disturbing any of the other coils whenever such removal becomes necessary.

Various modifications may be made in the device embodying my invention without departing from the s irit and scope thereof and I desire that only such limitations shall be placed thereon as are imposed by the prior art or are specifically set forth 1n the appended claims.

I claim as my invention:

1. In an electric furnace com rising a lurality of refractory walls enc osing a rnace chamber, in combination, a pair of spaced, elongated. refractory, supportin members supported by one of said walls an rejecting into said chamber, said members aving a plurality of pockets in the opposing faces adjacent the outer edge, and a flattened helix of resistor wire having its rounded edge portions located in said pockets and suplrted by said refractory supporting mem rs.

2. In an electric furnace comprising a lurality of refractory walls enc osing a rnace chamber, in combination, an elongated, relatively narrow. refractory member supported by and projecting from one of said walls and having a plurality of relatively shallow pockets in one face thereof adjacent to the outer edge. a second elongated, relatively narrow, refractory member, supported by and rejecting from said w ll in parallel-spaceri) relation to said firs member and having a plurality of pockets in one face thereof adjacent to the outer edge, the kets in said second member being shal ower than the pockets in said first member and la helically Wound coil of resistor wire hav ing fiat, substantially parallel sides and rounded edge portions, the rounded edge kportions only being located in said pockets to support the resistor. coil.v

B. In an electric furnace, in combimition, a pair of relatively narrow, elongated, rew fractory supporting members located in parallel-spaced relation relatively to each other and having a plurality of spaced pockets in their opposing fa'ces located adjacent to oner edge thereof, and doublelayer coil oit resistor Wire having relatively small portions of each turn located in said pockets and supported by said refractory supporta ing members.

4. In an electric furnace comprising a plu rality of walls enclosing a furnace chamber.V

in combination, a pair of relatively narrow, elongated,'refractory supporting members located in parallel-spaced relation relative` ly to each other in one of said Walls and proi jecting into said chamber, said men'rbers having a plurality of spaced pockets in their opposing faces adjacentjhe outer edgesl thereof. and al helically wound coil of re sister wire having fiat, substantially parallel. sides and rounded edge portions supported 4by said pair of refractory members, said coil being placed in its proper operative position relatively Ato said supporting members by a lateral and tilting movement thereof.

5. In an electric furnace comprising a plurality of Walls enclosing a furnace chamber, in combination, a pair of relatively narrow, elongated, refractory supporting members iocated in parallel-spaced relation relativelyv to each other in one of said walls and projecting into said chamber. said members having a. plurality of spaced pockets in their opposing faces adjacent the outer edges thereof, and a helieally wound coil of rc' sister Wire having flat, substantially paratA lel, sides and rounded edge portions sup ported by said pair of refractory members, said coil being placed in ils proper operaA tire position relatively to said supporting members by first placing one edge portion in operative engagement` with one of said refractory supporting members and then placing the other edge portion in operative engagement with the other supporting membei'.

6. In an electric furnace comorising a plurality of refractory walls enc osing a fur nace chamber, in combination an elongated, relatively narrow, refractory member sup-y ported by and projecting from one of said Walls and having a plurality of relatively shallow pockets in one face thereof adjacent to the outer edge, a second elongated, relatively narrow, refractory member, supportetl by and rejecting from said wall in par allel-spacecl) relation to said firstk member and `having a plurality of pockets in one 'face thereof adjacent to the outer edge, the pockets m said second member being shallower than the pockets in said member,-

and beiically Woundcoii of resistor W' e lhaving flat. substaritiallj,Y parallel sides and rounded edge portions supported by said pair ot refractory members, said coil being placeabic its proper operative position by first piaeing one edge portion in the deeper ot the li supporting member and then placing the other portion in the shallovrer pockets ot the s la member a laterai and tilting movement of the coii.

7, In f. electric furnace, in combination, a helicailjf Wound c. i Wire electric i111 wound coil roun 1 edge, portions, and pair of relie tirer, narrow, elongated, ret'zictoiy,si1p

Aporting members toc-ated in parallel-spaced relation tively to cach other operatively engaging the rounded edge'portions of 'said coil to support the same and having embodyin means for positively locating the adjacent turns of said coil in spaced relation to y'each other, and for permitting the free expansion ot' said side portions of the coil during the operation thereof, the coil 'being placeable in its proper operative posit-ion relatively to the supporting members by a lateral and tilting movement thereof.

It). In an electric furnace, in combination, a helicaliy `wound flattened coil et resistor wire. and a pair of refractory supporting members therefor operativeiv engaging the outer surface oit' a small portion only of said coil and having embodying means comprising receiving pocacts for permitting free lateral expansion of said coils and for ing mckets o f different depth in the two 10 proven longitudinal movement of the mem rs for permitting free lateral expen- 'mdividm turns of said coil. sion of seid coils whilmpreventing longitu- 11. In an electric furnace, in combination, dinul movement thereof.`

a helically wound coil of resistor wire, and s In testimony whereof, I have hereunto subpnir of refrectory supporting members scribed my neme this 13th dey of August, ll

- thereforoperativel engaging the outer sur- 1923.

face of e small ge portion only of said coil andhaving embodying menne, comprisv l FRANK THORNTON, JB. 

